Book Recommendation on the Elite Influence of World War I

For those who like a digital version, has good point summaries at the end of each chapter: https://dn790001.ca.archive.org/0/items/docherty-macgregor-prolonging-the-agony-how-the-international/Docherty_&_Macgregor_Prolonging_the_Agony_How_the_International.pdf